1. Field of the Invention
The present invention relates to a method of generating a liquid mist for producing phantom targets or camouflage.
2. Prior Art
It is previously known that a liquid mist, for example in the form of a water mist, can be used for camouflaging an object or for producing phantom targets, if an object is covered by a water mist, detection by means of IR measurement is rendered more difficult. By regulating the temperature of the water which is used for generating the mist it is also possible to generate a mist having a temperature which makes it an effective phantom target, for instance for an IR target seeker.
The patent document EP 0 221 489 B shows an example of a device for producing phantom targets and camouflage by generation of a liquid mist. With this device the mist is generated by means of water projectors provided with atomiser nozzles. The liquid is discharged through the nozzles in the shape of very small drops.
The known technique of generating a liquid mist by means of atomiser nozzles has several shortcomings, it takes a relatively long time to generate a completely covering mist, and therefore a long forewarning time is required in case of an attack from homing missiles. Furthermore, the water consumption is very high. In cold weather there is also a risk that the nozzles will be blocked up by ice and that the protected installation will be covered with ice.
The object of the invention is to produce a new technique of generating a liquid mist for producing camouflage or phantom targets, which overcomes the problems experienced with the previously known technique.
According to the invention, the liquid mist is generated by launching water, by means of a water cannon, at such a high velocity that initially the liquid is held together in a liquid packet in order to decompose after a certain distance, under the effect of the air resistance, and atomize into small liquid.
With the new technique, a shorter time delay is obtained between the initiation and the moment at which the liquid mist is fully developed. The water consumption is low, and therefore the technique is also suitable for use on mobile installations on land. As the formation of the mist takes place at a certain distance from the protected installation and the launching device has no atomizer nozzles, there will be less problems with ice formation than with the previously known technique. Furthermore, the launched liquid packet is relatively insensitive to the effects of wind, and therefore it will be easier to achieve the mist formation at a predetermined location in space.
These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.